ZfN: Search Results

1	Author	Jochen Heukeshoven, Rudolf Demick	Requires cookie*
	Title	Chemische Analyse und Struktur des Poliovirus. I. Cystein/Cystin Gehalt, vollständige Aminosäureanalyse und Hydrophobizität von Poliovirus und seinen natürlichen leeren Kapsiden Chemical Analysis and Structure of Poliovirus. I. Cysteine/Cystine Content, Complete Amino Acid Analysis and Hydrophobicity of Poliovirus and Its Naturally Occurring Empty Capsids
	Abstract	The cysteine content o f poliovirus particles and naturally occuring empty capsids was determined by two methods: (1) reaction with vinylpyridine and subsequent amino acid analyses and (2) treatment with 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) and measurement in the change of absorption. Both methods were performed under dissociating conditions in order to expose all sulfhydryl groups. Poliovirus, type 1, strain Mahoney, contains 10-11 cysteine/cystine residues per protomer, irrespective o f the use o f virus particles or empty capsids. Poliovirus, type 3, strain Saukett, contains 1 2 -1 3 cysteine/cystine residues per protomer. Poliovirus particles are completely free o f disulfide bridges, whereas empty capsids contain 2 -4 cystine residues/protomer. N o sulfhydryl groups are present on the surface o f the virus particle, because of lack of reaction with DTNB. The tryptophan content was determined to be 13 ± 1 residues/protomer. By amino acid analysis under controlled hydrolyzing conditions 12 residues/protomer were found, whereas formylation in hydrochloric acid/formic acid revealed 14 residues/protomer; 13 tryptophan residues were calculated from the tyrosine-tryptophan relation and the optical density at 293.5 nm and 280 nm. The following parameters of poliovirus particles were calculated from the improved and complete amino acid analysis and the cysteine and tryptophan content: 1. The molecular weight of a protomer to be 92 700 ± 900 Dalton and of the poliovirus particle, type 1, strain Mahoney, to be 7.97 x 10® Dalton. 2. The relative hydrophobicity o f the poliovirus polypeptide to be 1.18. 3. The extinction coefficients o f poliovirus = 7 4 and o f empty capsids E\ g° = 16.2 ± 0.2.
	Reference	Z. Naturforsch. 36c, 164—172 (1981); eingegangen am 21. August 1980
	Published	1981
	Keywords	Poliovirus, Empty Capsids, Amino Acid Analysis, Extinction Coefficient, Hydrophobicity
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	TEI-XML for	default:Reihe_C/36/ZNC-1981-36c-0164.pdf
	Identifier	ZNC-1981-36c-0164
	Volume	36

2	Author	M. Ark, P. Staves, DavidP. Bloch	Requires cookie*
	Title	Evolution of E. coli tRNAI,e: Evidence of Derivation from Other tRNAs
	Abstract	Two E. coli tR N A Ile sequences were com pared against those of 36 other E. coli tRN As. tR N A Ile 1 was found to bear high similarity with tR N A Val 1 (E = 1.11 x 10" 18) while tR N A Ile 2 had the greatest match (£ = 3 .4 0 x 10" 19) with tR N A Lysl (E is the expected num ber of such matches, per search, based on coincidence). These m atches, which we consider to represent homologies, extend from base 7 to base 67 in the form er and base 7 to the end (76) in the latter pair. These results coupled wim otners on tne lower activity ot isoleucine in reactions postulated to be im portant in primitive protein synthesis (i.e. esterification reactions and non-enzym atic activation by A TP [1—3]) lead us to propose that isoleucine was included among the proteinaceous amino acids, and received its anticodonic assignment, relatively late in evolution through m utation of tR N A s previously employed for other amino acids.
	Reference	Z. Naturforsch. 42c, 129 (1987); received June 13/September 4 1986
	Published	1987
	Keywords	Transfer R N A, Evolution, Codon Assignments, Sequence Homology, Hydrophobicity
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	TEI-XML for	default:Reihe_C/42/ZNC-1987-42c-0129.pdf
	Identifier	ZNC-1987-42c-0129
	Volume	42

3	Author	ChunheX. Ua, Yong Zhub, Govindjeeac	Requires cookie*
	Title	Differential Inhibition and Rephasing of Photosystem II Electron Acceptor Side by Monohalogenated Acetates of Different Hydrophobicity
	Abstract	We demonstrate here that monohalogenated acetates (M F A , m onofluoroacetate; M CA, m onochloroacetate; M BA, monobrom oacetate) are unique probes o f the electron acceptor side o f the photosystem II (PS II) reaction center: (1) they differentially inhibit the reoxidation o f the reduced primary plastoquinone electron acceptor, QA~, by the secondary plastoquinone electron acceptor QB, and increase the equilibrium [QA_] in the order: M BA > M C A > M FA; and (2) M CA and M BA rephase the PS II electron acceptor side, a rather unusual effect. This results in flash number dependence o f [QA_] with maxima at even flashes to change to odd flashes. Furthermore, we demonstrate a correlation between the inhibitory activity o f the halo-genated acetates with their hydrophobicity (i.e., partition coefficient).
	Reference	Z. Naturforsch. 47c, 711—7 (1992); received June 2 1992
	Published	1992
	Keywords	M onohalogenated Acetates, Photosystem II, Two Electron Gate, Hydrophobicity, Bicarbonate Effect
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	TEI-XML for	default:Reihe_C/47/ZNC-1992-47c-0711.pdf
	Identifier	ZNC-1992-47c-0711
	Volume	47